Quick Facts: Mariner 9

Mission Introduction

The Mariner Mars mission of 1971 was planned to consist of two spacecraft to orbit Mars on complementary missions, but due to the failure of Mariner 8 to launch properly, only one spacecraft was available. Mariner 9 combined mission objectives of both Mariner 8 (mapping 70% of the Martian surface) and Mariner 9 (a study of temporal changes in the Martian atmosphere and on the Martian surface). For the survey portion of the mission, the planetary surface was to be mapped with the same resolution as planned for the original mission, although the resolution of pictures of the polar regions would be decreased due to the increased slant range. The variable features experiments were changed from studies of six given areas every 5 days to studies of smaller regions every 17 days. On November 13, 1971, Mariner 9 became the first spacecraft to orbit another planet.

LASP Roles

LASP Instrument

The Mariner 9 ultraviolet spectrometer (UVS) experiment was designed to receive UV radiation (1100 to 3520 A) from the surface and atmosphere of Mars, scan selected bands of this radiation, and provide an intensity value as a function of wavelength on the basis of scan-cycle time. The scientific objectives of this experiment fell into two broad categories, UV cartography and UV aeronomy. The UV cartography involved measurements in the UV of the local atmospheric pressure over the major portion of the planet, and the local ozone concentration. The UV aeronomy involved measurements in the UV of the composition and structure of the upper atmosphere as a function of latitude, longitude, and time, and the variability of the rate of escape of atomic hydrogen from the exosphere. In addition, when Mars was occulted from the instrument FOV, observations of strong stellar sources of UV were made.

For more information about the Ultraviolet Spectrometer aboard the Mariner 9 mission, visit: